Make sure all the ingredients are at room temperature before beginning
Mix the cocoa powder, water and coffee to make a paste like consistency and set aside
Beat the sugar and butter until pale and fluffy
Add the eggs one at a time and beat until all are incorporated on a high speed
Add the yoghurt and vanilla essence and beat again
Add the flour, baking powder, soda and salt and beat on a low speed until combined
Add the batter to a greased and lined loaf tin (24in × 14in), reserving ⅓ of the batter
Add the cocoa paste to the reserved batter and mix well
Add the chocolate batter on top of the plain batter and spread evenly covering the top
Fold and marble the batter together
Bake at 170°C for 40 minutes or until a skewer comes out clean
Allow to cool in the pan
Slice and enjoy
